Is there a way to make stitching?
With version 2.78, you can now draw curves onto surfaces.

To use it:


Add a Path curve in object mode (Shift + A >> Curve >> Path).
Enter into edit mode (TAB).
T to show the Tools panel.
Under the Options tab set your Projection Depth to Surface.
Under the Create tab click Draw Curve or alternatively Shift + A >> Draw Curve.


NOTE: you can play with the Tolerance under the Options tab to get settings to your liking. After creating your desired curve, delete the verts that make up the original path.


Create a thread mesh design.
Add an Array modifier to your thread mesh, setting its Fit Type to the curve object.
Add a Curve modifier to the thread mesh, setting its Object to the same curve object in the Array modifier.


For me, I picked the start point of my curve as being the origin of the curve, and set its position to the origin of the thread mesh, then played with the Constant Offset of the Array modifier.

Here's was my results: